2anj

Crystal Structure of the Glur2 Ligand Binding Core (S1S2J-Y450W) Mutant in Complex With the Partial Agonist Kainic Acid at 2.1 A Resolution

spinqualitylabelsall models 2anj, resolution 2.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2anj is a 1 chain structure with sequence from Rattus norvegicus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.1Å Ligands: KAI Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function GRIA2_RAT Receptor for glutamate that functions as ligand-gated ion channel in the central nervous system and plays an important role in excitatory synaptic transmission. L-glutamate acts as an excitatory neurotransmitter at many synapses in the central nervous system. Binding of the excitatory neurotransmitter L-glutamate induces a conformation change, leading to the opening of the cation channel, and thereby converts the chemical signal to an electrical impulse. The receptor then desensitizes rapidly and enters a transient inactive state, characterized by the presence of bound agonist. In the presence of CACNG4 or CACNG7 or CACNG8, shows resensitization which is characterized by a delayed accumulation of current flux upon continued application of glutamate. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Binding of an agonist to the 2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)-propionic acid (AMPA) receptor family of the glutamate receptors (GluRs) results in rapid activation of an ion channel. Continuous application results in a non-desensitizing response for agonists like kainate, whereas most other agonists, such as the endogenous agonist (S)-glutamate, induce desensitization. We demonstrate that a highly conserved tyrosine, forming a wedge between the agonist and the N-terminal part of the bi-lobed ligand-binding site, plays a key role in the receptor kinetics as well as agonist potency and selectivity. The AMPA receptor GluR2, with mutations in Tyr-450, were expressed in Xenopus laevis oocytes and characterized in a two-electrode voltage clamp setup. The mutation GluR2(Y450A) renders the receptor highly kainate selective, and rapid application of kainate to outside-out patches induced strongly desensitizing currents. When Tyr-450 was substituted with the larger tryptophan, the (S)-glutamate desensitization is attenuated with a 10-fold increase in steady-state/peak currents (19% compared with 1.9% at the wild type). Furthermore, the tryptophan mutant was introduced into the GluR2-S1S2J ligand binding core construct and co-crystallized with kainate, and the 2.1-A x-ray structure revealed a slightly more closed ligand binding core as compared with the wild-type complex. Through genetic manipulations combined with structural and electrophysiological analysis, we report that mutations in position 450 invert the potency of two central agonists while concurrently strongly shaping the agonist efficacy and the desensitization kinetics of the AMPA receptor GluR2. A binding site tyrosine shapes desensitization kinetics and agonist potency at GluR2. A mutagenic, kinetic, and crystallographic study.,Holm MM, Naur P, Vestergaard B, Geballe MT, Gajhede M, Kastrup JS, Traynelis SF, Egebjerg J J Biol Chem. 2005 Oct 21;280(42):35469-76. Epub 2005 Aug 15. PMID:16103115 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Glutamate receptor 3D structures

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